Tritylated alkyl aryl ethers

ABSTRACT

A compound having formula (Ph 3 C) m Ar(R 1 ) j (OR 2 ) n , wherein Ph represents a phenyl group, Ar is an aromatic ring system having from six to twenty carbon atoms, R 1  and R 2  independently are C 1 -C 18  alkyl or C 4 -C 18  heteroalkyl, m is one or two, j is an integer from one to four and n is an integer from one to three.

This invention relates to new compounds useful in a method for markingliquid hydrocarbons and other fuels and oils.

Marking of petroleum hydrocarbons and other fuels and oils with variouskinds of chemical markers is well known in the art. A variety ofcompounds have been used for this purpose, as well as numeroustechniques for detection of the markers, e.g., absorption spectroscopyand mass spectrometry. For example, U.S. Pat. No. 7,858,373 disclosesthe use of a variety of organic compounds for use in marking liquidhydrocarbons and other fuels and oils. However, there is always a needfor additional marker compounds for these products. Combinations ofmarkers can be used as digital marking systems, with the ratios ofamounts forming a code for the marked product. Additional compoundsuseful as fuel and lubricant markers would be desirable to maximize theavailable codes. The problem addressed by this invention is to findadditional markers useful for marking liquid hydrocarbons and otherfuels and oils.

STATEMENT OF INVENTION

The present invention provides a compound having formula(Ph₃C)_(m)Ar(R¹)_(j)(OR²)_(n), wherein Ph represents a phenyl group, Aris an aromatic ring system having from six to twenty carbon atoms, R¹and R² independently are C₁-C₁₈ alkyl or C₄-C₁₈ heteroalkyl, m is one ortwo, j is an integer from one to four and n is an integer from one tothree.

The present invention further provides a method for marking a petroleumhydrocarbon or a liquid biologically derived fuel; said methodcomprising adding to said petroleum hydrocarbon or liquid biologicallyderived fuel at least one compound having formula(Ph₃C)_(m)Ar(R¹)_(j)(OR²)_(n), wherein Ph represents a phenyl group, Aris an aromatic ring system having from six to twenty carbon atoms, R¹and R² independently are C₁-C₁₈ alkyl or C₄-C₁₈ heteroalkyl, m is one ortwo, j is an integer from one to four and n is an integer from one tothree; wherein each compound having formula(Ph₃C)_(m)Ar(R¹)_(j)(OR²)_(n) is present at a level from 0.01 ppm to 20ppm.

DETAILED DESCRIPTION

Percentages are weight percentages (wt %) and temperatures are in ° C.,unless specified otherwise. Concentrations are expressed either in partsper million (“ppm”) calculated on a weight/weight basis, or on aweight/volume basis (mg/L); preferably on a weight/volume basis. Theterm “petroleum hydrocarbon” refers to products having a predominantlyhydrocarbon composition, although they may contain minor amounts ofoxygen, nitrogen, sulfur or phosphorus; petroleum hydrocarbons includecrude oils as well as products derived from petroleum refiningprocesses; they include, for example, crude oil, lubricating oil,hydraulic fluid, brake fluid, gasoline, diesel fuel, kerosene, jet fueland heating oil. Marker compounds of this invention can be added to apetroleum hydrocarbon or a liquid biologically derived fuel; examples ofthe latter are biodiesel fuel, ethanol, butanol, ethyl tert-butyl etheror mixtures thereof. A substance is considered a liquid if it is in theliquid state at 20° C. A biodiesel fuel is a biologically derived fuelcontaining a mixture of fatty acid alkyl esters, especially methylesters. Biodiesel fuel typically is produced by transesterification ofeither virgin or recycled vegetable oils, although animal fats may alsobe used. An ethanol fuel is any fuel containing ethanol, in pure form,or mixed with petroleum hydrocarbons, e.g., “gasohol.” An “alkyl” groupis a substituted or unsubstituted hydrocarbyl group having from one totwenty-two carbon atoms in a linear, branched or cyclic arrangement.Substitution on alkyl groups of one or more OH or alkoxy groups ispermitted; other groups may be permitted when specified elsewhereherein. Preferably, alkyl groups are saturated. Preferably, alkyl groupsare unsubstituted. Preferably, alkyl groups are linear or branched. An“aryl” group is a substituent derived from an aromatic hydrocarboncompound. An aryl group has a total of from six to twenty ring atoms,unless otherwise specified, and has one or more rings which are separateor fused. Substitution on aryl groups of one or more alkyl or alkoxygroups is permitted. A “heteroalkyl” group is an alkyl group in whichone or more methylene groups has been replaced by O or S. Preferably,heteroalkyl groups contain from one to six O or S atoms, preferably fromone to four, preferably from one to three. The methylene groups replacedby O or S were bonded to two other carbon atoms in the correspondingalkyl group. Preferably, heteroalkyl groups do not contain S atoms.Preferably, heteroalkyl groups are saturated. Heteroalkyl groups may besubstituted by OH or C₁-C₁₈ alkoxy groups, preferably OH or C₁-C₆ alkoxygroups, preferably hydroxy or C₁-C₄ alkoxy groups. Examples ofheteroalkyl groups include oligomers of ethylene oxide, propylene oxideor butylene oxide having two to six units of the alkylene oxide(preferably two to four, preferably two or three) and a terminal hydroxyor C₁-C₆ alkoxy group (preferably hydroxy or C₁-C₄ alkoxy, preferablyhydroxy or methoxy, preferably hydroxy); an example of an ethylene oxideoligomer is —{(CH₂)₂O}_(x)R³, where x is an integer from two to six andR³ is hydrogen or C₁-C₆ alkyl. Preferably, j is from two to four,preferably two or three. Preferably, R³ is hydrogen or C₁-C₄ alkyl,preferably hydrogen or methyl, preferably hydrogen. Preferably, thecompounds of this invention contain elements in their naturallyoccurring isotopic proportions.

Ar is an aromatic ring system having from six to twenty carbon atoms andwhose substituents include Ph₃C, R¹ and OR² groups, preferably one inwhich the only substituents are Ph₃C, R¹ and OR² groups. Preferably, Aris a C₆-C₁₂ hydrocarbyl aromatic ring system. Preferably, Ar is benzene,naphthalene, biphenyl, phenyl ether, diphenylmethane or one of thepreceding systems substituted with alkyl and/or alkoxy groups;preferably benzene. Preferably, n is one or two, preferably one.Preferably, m is one. Preferably, j is from one to three, preferably oneor two. Preferably, R¹ is C₂-C₁₂ alkyl or C₄-C₁₂ heteroalkyl, preferablyC₂-C₁₂ alkyl, preferably C₃-C₈ alkyl or C₄-C₈ heteroalkyl, preferablyC₂-C₈ alkyl, preferably C₃-C₈ alkyl, preferably C₃-C₆ alkyl, preferablyC₂-C₆ alkyl, preferably C₂₋₅ alkyl, preferably sec-butyl, t-butyl orisopropyl. Preferably, R¹ is saturated. Preferably, R¹ is linear orbranched. Preferably, R² is C₂-C₁₈ alkyl or C₄-C₁₈ heteroalkyl,preferably C₄-C₁₈ alkyl or C₄-C₁₈ heteroalkyl, preferably C₂-C₁₈ alkyl,preferably C₃-C₁₈ alkyl or C₄-C₁₂ heteroalkyl, preferably C₃-C₁₈ alkyl,preferably C₄-C₁₈ alkyl, preferably C₆-C₁₈ alkyl, preferably C₆-C₁₆alkyl, preferably C₁₀-C₁₄ alkyl. Preferably, R² is saturated.Preferably, R² is linear or branched, preferably branched.

In using the compounds of this invention as markers, preferably theminimum amount of each compound added to a liquid to be marked is atleast 0.01 ppm, preferably at least 0.02 ppm, preferably at least 0.05ppm, preferably at least 0.1 ppm, preferably at least 0.2 ppm.Preferably, the maximum amount of each marker is 50 ppm, preferably 20ppm, preferably 15 ppm, preferably 10 ppm, preferably 5 ppm, preferably2 ppm, preferably 1 ppm, preferably 0.5 ppm. Preferably, the maximumtotal amount of marker compounds is 100 ppm, preferably 70 ppm,preferably 50 ppm, preferably 30 ppm, preferably 20 ppm, preferably 15ppm, preferably 12 ppm, preferably 10 ppm, preferably 8 ppm, preferably6 ppm, preferably 4 ppm, preferably 3 ppm, preferably 2 ppm, preferably1 ppm. Preferably, a marker compound is not detectable by visual meansin the marked petroleum hydrocarbon or liquid biologically derived fuel,i.e., it is not possible to determine by unaided visual observation ofcolor or other characteristics that it contains a marker compound.Preferably, a marker compound is one that does not occur normally in thepetroleum hydrocarbon or liquid biologically derived fuel to which it isadded, either as a constituent of the petroleum hydrocarbon or liquidbiologically derived fuel itself, or as an additive used therein.

Preferably, the marker compounds have a log P value of at least 3, whereP is the 1-octanol/water partition coefficient. Preferably, the markercompounds have a log P of at least 4, preferably at least 5. Log Pvalues which have not been experimentally determined and reported in theliterature can be estimated using the method disclosed in Meylan, W. M &Howard, P. H., J. Pharm. Sci., vol. 84, pp. 83-92 (1995). Preferably thepetroleum hydrocarbon or liquid biologically derived fuel is a petroleumhydrocarbon, biodiesel fuel or ethanol fuel; preferably a petroleumhydrocarbon or biodiesel fuel; preferably a petroleum hydrocarbon;preferably crude oil, gasoline, diesel fuel, kerosene, jet fuel orheating oil; preferably gasoline.

Preferably, the marker compounds are detected by at least partiallyseparating them from constituents of the petroleum hydrocarbon or liquidbiologically derived fuel using a chromatographic technique, e.g., gaschromatography, liquid chromatography, thin-layer chromatography, paperchromatography, adsorption chromatography, affinity chromatography,capillary electrophoresis, ion exchange and molecular exclusionchromatography. Chromatography is followed by at least one of: (i) massspectral analysis, and (ii) FTIR. Identities of the marker compoundspreferably are determined by mass spectral analysis. Preferably, massspectral analysis is used to detect the marker compounds in thepetroleum hydrocarbon or liquid biologically derived fuel withoutperforming any separation. Alternatively, marker compounds may beconcentrated prior to analysis, e.g., by distilling some of the morevolatile components of a petroleum hydrocarbon or liquid biologicallyderived fuel.

Preferably, more than one marker compound is present. Use of multiplemarker compounds facilitates incorporation into the petroleumhydrocarbon or liquid biologically derived fuel of coded informationthat may be used to identify the origin and other characteristics of thepetroleum hydrocarbon or liquid biologically derived fuel. The codecomprises the identities and relative amounts, e.g., fixed integerratios, of the marker compounds. One, two, three or more markercompounds may be used to form the code. Marker compounds according tothis invention may be combined with markers of other types, e.g.,markers detected by absorption spectrometry, including those disclosedin U.S. Pat. No. 6,811,575; U.S. Pat. App. Pub. No. 2004/0250469 and EPApp. Pub. No. 1,479,749. Marker compounds are placed in the petroleumhydrocarbon or liquid biologically derived fuel directly, oralternatively, placed in an additives package containing othercompounds, e.g., antiwear additives for lubricants, detergents forgasoline, etc., and the additives package is added to the petroleumhydrocarbon or liquid biologically derived fuel.

The compounds of this invention may be prepared by methods known in theart, e.g., alkylation of alkyl phenols or alkyl polyhydroxyaromaticswith trityl halide or alcohol, followed by alkylation with organichalides in the presence of base. For example, tritylated alkyl phenolicethers may be prepared according to the following reaction scheme,

Corresponding compounds in which Ar is not benzene may be prepared fromthe corresponding substituted aromatic starting materials.

Examples

A typical procedure for the synthesis of a trityl alkyl phenol isillustrated by:

2-(sec-Butyl)-4-tritylphenol

A 250 mL 1-neck flask was equipped with a magnetic stirrer and a refluxcondenser with nitrogen blanket. The flask was charged with 6.52 grams(0.025 moles) of trityl alcohol, 3.77 grams (0.025 moles) ofo-sec-butylphenol, and 50 mL of glacial acetic acid. The mixture wasstirred under nitrogen at room temperature to give a clear, yellowsolution. Concentrated sulfuric acid (5 mL) was then added in oneportion. The solution immediately became dark red-brown. The solutionwas stirred at room temperature for 2 days, during which time solidsseparated out. The reaction mixture was filtered, and the solids werewashed on the filter with several portions of water. After drying in avacuum oven at 65° C. for 3 hours, the yield of product was 7.34 grams(75% yield). MP=135-136° C. GPC analysis showed a purity of >99%. Thestructure was confirmed by IR, ¹H- and ¹³C-NMR analyses.

The trityl alkyl phenol compounds prepared by this procedure are listedin Table 1 below.

TABLE 1 Synthesis Data for Trityl Alkyl Phenols Trityl Phenol MP, % (T =triphenylmethyl) Mol. Wt. ° C. Yield [CAS]

392.53 136-136 75 (none)

448.64 82-91 94 (none)

392.52 181-182 93 60043-12-1

392.52 153-161 35 97358-11-7

448.64 157-161 89 68869-56-7

448.64 188-200 16 (none)

378.51 145-147 82 (none)

420.59 142-143 91 (none)

A typical procedure for the synthesis of a trityl alkyl aryl ether isillustrated by:

(3-(sec-Butyl)-4-(decyloxy)phenyl)methanetrityl)tribenzene (DecTsBuPh

A 500 mL 3-neck flask was equipped with a magnetic stirrer, a refluxcondenser with nitrogen blanket, a heating mantle with a temperaturecontroller, and a thermocouple. The flask was charged with 39.32 grams(0.1 mole) of TritosBuPhOH, 6.64 grams (0.1 mole) of 85% potassiumhydroxide pellets, and with 250 mL of dimethyl sulfoxide. The mixturewas stirred under nitrogen while being heated to 110° C. When all of thepotassium hydroxide had dissolved, the dark colored reaction mixture wascooled to 50° C. Bromodecane (20.7 mL, 22.12 grams, 0.1 mole) was thenadded in one portion. An exotherm to about 60° C. was observed. Heatingat 60° C. was maintained for 8 hours, then the reaction mixture waspoured into about 1200 mL of water containing about 2 grams of potassiumhydroxide pellets and about 15 grams of sodium chloride. Toluene (about300 mL) was added, and the mixture was stirred at room temperature forabout 1 hour. The mixture was transferred to a separatory funnel, andthe layers were separated. The aqueous layer was washed with 1×100 mL oftoluene, and the washings were combined with the original toluene layer.The toluene solution was dried over anhydrous magnesium sulfate. Afterfiltration, the toluene was removed by rotary evaporation to give 49.48grams of product as a red oil. Yield was 93%. The structure wasconfirmed by IR, ¹H- ¹³C-NMR, and GC/MS analyses.

GC/MS Studies:

Stock solutions of each candidate were prepared in dichloromethane(DCM). These solutions were used to establish GC retention times and MSfragmentation patterns, to determine linearity vs. concentration curvesfrom 100 to 1000 ppb, and to demonstrate repeatability and accuracy at500 ppb concentrations. GC/MS results are shown in Tables 2 and 3.

GC/MS Parameters:

-   -   Column: Agilent DB 35 m, 15.0 m×0.25 mm×0.25μ    -   Flow Rate: 1.5 mL/min. He carrier gas    -   Oven: initial: 100° C.    -   Ramp 1: 20° C./min to 280° C.; Hold: 10 min.    -   Ramp 2: 20° C./min to 340° C.; Hold: 6 min    -   Inlet Temp.: 280° C.    -   Insert: Splitless; Vent: 15 min, Single taper, glass wool,        deactivated, 5062-3587    -   Injection Volume: 3 μL; Viscosity: 5 sec., Plunger: fast    -   Mass Transfer Line Temp.: 280° C.    -   MS Quad: 200° C.; MS Source: 250° C.    -   Solvent Delay: 18.5 min.

TABLE 2 Synthesis Data for Trityl Alkyl o-sec-Butyl Phenol Ethers

GC Ret Mol. Time MS Major R₂ Wt. MP, ° C. % Yield min. Mass, m/e n-C₆H₁₃476.69 93-97 81 14.2 476, 399 n-C₁₀H₂₁ 532.81 oil 93 20.99 532, 455n-C₁₂H₂₅ 560.85 oil 87 22.25 560, 483 n-C₁₄H₂₉ 588.9 oil 88 23.49 588,511 n-C₁₆H₃₃ 616.96 49-54 82 25.16 616, 539

TABLE 3 Synthesis Data for Trityl Dodecyl Aryl Ethers GC Ret MS TrityDodecyl Aryl Ether Mol. Time Major (T = triphenylmethyl) Wt. MP, ° C. %Yield min. Mass, m/e

616.96 oil 79 20.91 616, 539, 371

560.85 oil 100 22.32 560, 483, 315

560.85 oil 100 19.96 560, 377

616.96 oil 75 21.41 616, 371

616.96 114-119 43 616 448, 433

546.84 49-51 91 22.03 546, 469, 301

588.9 oil 91 20.64 588, 511, 343

TABLE 4 Stability and Extractability* Data for DecTsBuPh % ChangeStandard 0.00 5% NaOH 0.10 50% NaOH 0.60 5% H₂SO₄ −0.04 98% H₂SO₄ −1.842% Charcoal −0.76 5% Bleach 1.08 Iron Specks 1.76 Fuller's Earth 0.79*Test Protocols: 2000 mg/kg solution with internal standard was made inxylenes, then dosed with 5% by weight of 5% NaOH, 50% NaOH, 5% sulfuricacid and 98% sulfuric acid. It was also tested with 2% charcoal 5%bleach and 2% metal specs by wt/wt. The mixtures were stirred gently atroom temperature for 8 hours, then the solutions were analyzed by GC andcompared to the stock solution.

TABLE 5 Sunlight Stability Data* for DecTsBuPh Sunlight % ChangeStandard 0.00 Apr. 5, 2012 −1.90 Apr. 13, 2012 2.40 Apr. 23, 2012 0.90May 8, 2012 −1.40 May 15, 2012 1.80 *The marker sample was made at 2000mg/.l concentration with internal standard and checked by GC every weekfor changes in marker concentration.

Solubility Studies:

Solutions were made from 0.1 grams of marker candidate and 0.9 grams ofsolvent. The mixtures were warmed briefly to 60° C. to completelydissolve the marker candidate, then the solutions were cooled to roomtemperature. The solutions were then placed into a −10° C. freezer, andthe stability of the solutions was monitored for at least 7 days.

TABLE 6 Solubility Data for Trityl Alkyl o-sec-Butyl Phenol Ethers

SOLUBILITY BEHAVIOR^(a) ROOM R₂ SOLVENT 60 C. TEMP −10 C. C₆H₁₃ Aromatic200 sol sol xtls 4D DPGDME sol sol xtls 4D tetralin sol sol xtls 5D NMPsol sol xtls 5D DMAc sol sol xtls 4D 75:25 Aromatic 150:cyclohexanonesol sol sol 7D C₁₀H₂₁ Aromatic 200 sol sol sol 33D DPGDME sol sol sol33D tetralin sol sol sol 33D NMP sol sol sol 33D DMAc sol sol sol 33D75:25 Aromatic 200:cyclohexanone sol sol sol 33D 75:25 Aromatic150:cyclohexanone sol sol sol 33D C₁₂H₂₅ Aromatic 200 sol sol xtls 6DDPGDME sol sol sol 7D tetralin sol sol sol 7D NMP sol sol sol 7D DMAcsol sol sol 7D 75:25 Aromatic 150:cyclohexanone sol sol sol 7D C₁₄H₂₉Aromatic 200 sol sol sol 7D DPGDME sol sol sol 7D tetralin sol sol sol7D NMP sol sol sol 7D DMAc sol sol xtls 6D 75:25 Aromatic150:cyclohexanone sol sol sol 7D C₁₆H₃₃ Aromatic 200 sol sol sol 7DDPGDME sol sol sol 7D tetralin sol sol sol 7D NMP sol sol xtls 6D DMAcsol sol xtls 6D 75:25 Aromatic 150:cyclohexanone sol sol sol 7D ^(a)sol= soluble; xtls = crystals D = days DPGME is dipropylene glycolmono-methyl ether and NMP is N-methylpyrrolidone; AROMATIC 200 andAROMATIC 150 are mixed aromatic solvents available from Exxon MobilCorp.

TABLE 7 Solubility Data for Trityl Dodecyl Aryl Ethers SOLUBILITYBEHAVIOR^(a) Trity Dodecyl Aryl Ether ROOM (T = triphenylmethyl) SOLVENT60 C. TEMP −10 C.

75:25 Aromatic 200H:cyclohexanone 75:25 Aromatic 200H:o-sec-butylphenolsol sol sol sol sol 7D sol 7D

75:25 Aromatic 200H:cyclohexanone 75:25 Aromatic 200H:o-sec-butylphenolsol sol sol sol sol 7D sol 7D

75:25 Aromatic 200H:cyclohexanone 75:25 Aromatic 200H:o-sec-butylphenolsol sol sol sol sol 7D sol 7D

75:25 Aromatic 200H:cyclohexanone 75:25 Aromatic 200H:o-sec-butylphenolsol sol sol sol sol 7D sol 7D

75:25 Aromatic 200H:cyclohexanone 75:25 Aromatic200H:o-sec-butylphenolsol sol sol sol sol xtls 6D xtls 6D

75:25 Aromatic 200H:cyclohexanone 75:25 Aromatic 200H:o-sec-butylphenolsol sol sol sol sol 7D xtls 3D

75:25 Aromatic 200H:cyclohexanone 75:25 Aromatic 200H:o-sec-butylphenolsol sol sol sol xtls 4D sol 7D ^(a)sol = soluble; xtls = crystals D =days

1. A compound having formula (Ph₃C)_(m)Ar(R¹)_(j)(OR²)_(n), wherein Phrepresents a phenyl group, Ar is a C₆-C₁₂ hydrocarbyl aromatic ringsystem, R¹ is C₂-C₁₂ alkyl or C₄-C₁₂ heteroalkyl, R² is C₄-C₁₈ alkyl orC₄-C₁₈ heteroalkyl, m is one or two, j is an integer from one to threeand n is an integer from one to two.
 2. (canceled)
 3. (canceled) 4.(canceled)
 5. The compound of claim 1 in which Ar is a benzene ringsystem, j is one or two, n is one, R¹ is C₂-C₈ alkyl, R² is C₄-C₁₈ alkyland m is one.
 6. A method for marking a petroleum hydrocarbon or aliquid biologically derived fuel; said method comprising adding to saidpetroleum hydrocarbon or liquid biologically derived fuel at least onecompound having formula (Ph₃C)_(m)Ar(R¹)_(j)(OR²)_(n), wherein Phrepresents a phenyl group, Ar is an aromatic ring system having from sixto twenty carbon atoms, R¹ and R² independently are C₁-C₁₈ alkyl orC₄-C₁₈ heteroalkyl, m is one or two, j is an integer from one to fourand n is an integer from one to three; wherein each compound havingformula (Ph₃C)_(m)Ar(R¹)_(j)(OR²)_(n) is present at a level from 0.01ppm to 20 ppm.
 7. The method of claim 6 in which Ar is a C₆-C₁₂hydrocarbyl aromatic ring system, j is an integer from one to three andn is one or two.
 8. The method of claim 7 in which R¹ is C₂-C₁₂ alkyl orC₄-C₁₂ heteroalkyl.
 9. The method of claim 8 in which R² is C₄-C₁₈ alkylor C₄-C₁₈ heteroalkyl.
 10. The method of claim 9 in which Ar is abenzene ring system, j is one or two, n is one, R¹ is C₂-C₈ alkyl, R² isC₄-C₁₈ alkyl and m is one.